Why does my computer wake up from sleep

There are many possible reasons why your computer can wake up from sleep, including Windows Update, a scheduled task, or a device that is waking the computer, fortunately there are ways to work out what is causing the problem.

Check the wakeup reason

If you see your computer wake up from sleep, you can check the reason for the wakeup by typing in the following command in Command Prompt or PowerShell.

powercfg /lastwake

This will show you why the computer last woke, and will hopefully help pin down the reason for Windows waking from sleep. The remaining commands are tools to find possible causes, but this is the only command that give you a reason.

Another place you can check is Event Viewer to see if there are any error logs or indication as to why the computer woke from sleep.

A device misbehaving

A device on your computer could well be causing your computer to wake up, a common cause is an Ethernet port, you can check all of the devices that have the ability to wake the computer by running the following command from Command Prompt or PowerShell.

powercfg -devicequery wake_armed

This will show a list of devices that could be potential causes for waking your computer.

Once you find a device that is causing the computer to wake up, you can prevent the device from waking the computer in Device Manager by changing the Power Management settings

1. Open Device Manager
2. Find the device that is causing the issue, right-click on the device and select properties
   
3. Select the Power Management tab then uncheck "Allow this device to wake the computer"
   

A program on your computer

Some programs can have a wake timer configured, when a program wants to perform an action at a particular time, it can configure a wake timer which enables the program to wake the computer from sleep.

This could be a potential cause for the computer waking from sleep, you can view the list of programs on your computer that wake timers configured, by running the following command in PowerShell.

Get-ScheduledTask | where {$_.settings.waketorun}

Windows Update

It's possible that your computer could be waking due to Windows Updates, if you computer is waking up from Hibernation as opposed to Sleep, it could be due to a policy set in your computer, this is usually applied with group policy but on Windows 10 Home you can disable it in the registry.

Our script linked below makes it easy for you to disable this setting, you can also change it in the Windows registry at the following path:

HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\WindowsUpdate

Create a DWORD called "AUPowerManagement"

1 = Disable Wake during hibernation

0 = Enable Wake during hibernation

It could also be the Windows 10 Update Orchestrator service that is waking your computer from sleep, this can be stopped but its not a simple process.

To stop the Update Orchestrator you can attempt to run the following commands from an elevated Command Prompt, I don't recommend doing this step unless you know what you are doing.

sc stop "UsoSvc"

sc config "UsoSvc" start= disabled 

Windows Media Center 

If you have Windows media centre installed, this has a scheduled task that can be known to wake your computer, you can use our script to check if that could be the issue, or alternativley check in task scheduler for a task called "mcupdate_scheduled"

If the task exists, on the Conditions tab, uncheck the "Wake the computer to run this task" option.

Automatic Maintenance

Windows has a future built in called automatic maintenance, which performs maintenance tasks such as defragging your hard drive, or checking for updates at a certain time. This feature has the potential to wake your computer from sleep, you can disable this feature in control panel. Our script also provides an easy way to disable this feature.

You can also enable/disable this option in the Windows registry at the following path:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Schedule\Maintenance

Create a DWORD called "MaintenanceDisabled"

1 = Disable Automatic Maintenance

0 = Enable Automatic Maintenance

Disable Wake Timers

A wake timer is what allows a process to wake the computer from sleep, if the above suggestions don't help work out the cause, you might like to try disabling wake timers altogether and see if that makes a difference. You can change this in your power plan settings, or by using our Wakeup Diagnostics Script.

Wakeup Diagnostics Script

I have created a simple PowerShell script to address all of these issues, if you run this script next time your computer wakes up from sleep, it will tell you the reason. It will also tell you which processes and devices have the ability to wake your computer, and will give you the option to disable some of the other settings and policies mentioned in this article.

Please be aware that this script only gives the option to disable and not re-enable these policies, if you need to re-enable these policies, refer to the steps in this guide.

Wakeup Diagnostics Script